The Infernal Cup
by i5a8e11a
Summary: What would happen if Clary drank from the infernal cup? Or if she fell in love with Sebastian and left Jace? Clary is with Sebastian and Jace and amatis is brought out to drink from the infernal cup. What will Clary do? Abandon Amatis or save her? Simon and others are on there way to help. Will they be there in enough time?
1. Clary is Evil?

As Clary and Sebastian arrived at the seventh sacred sight Jace had already started giving his speech. As Jace finished his speech and introduced Sebastian and Clary, Sebastian started talking.

" My followers and comrades, the Clave has forcefully made us do many things and has betrayed us many times. I hope to change that. We can destroy the Nephilim once and for all, Lilith will give us great power! Power strong enough to rule the world! I will show you this power up close! Bring her to me!"

Everyone created a path. Then Clary saw Amatis she was limping and chained with someone forcing her to move forward. Clary wanted to scream, but she couldn't make a sound. Then Amatis looked right at Clary and Clary could see the sorrow and disappointment in her face. Then Clary ran in front of Amatis, Jace just missing her arm by inches.

"Sebastian don't do this!" Clary screamed while crying, "Please don't do me instead!"

Sebastian smiled, "Fine, if you insist little sister."

Then Sebastian started to raise Lilith. As she appeared she looked at her son with pride and joy.

"I have been waiting my son, I will lend you this marvelous power and as you share it I will become stronger and rise once again at my full potential!"

Lilith poured her blood into to the infernal cup, it was black as night. Then Lilith disappeared. The man holding Amatis came and held Clary down. Sebastian smiled and forced the cup to Clary's lips.

Clary gulped down the repulsive black ichor as her body began to shake. She felt the worst pain she had ever felt, it seemed as though she was dying. She screamed, her throat raw. The scream was horrid and blood curdling. It felt as though her body was being ripped in half.


	2. Clary x Sebastian

The pain suddenly stopped. Clary felt stronger, more confident and unlike her usual self, she felt like she could do anything and what she wanted to do was destroy the Nephilim. She started laughing, it sounded wicked and terrifying. Then she look at Sebastian, her brother and realized that her heart begged for him, she wanted him more than anything in the world. She wanted him and she would have him.

Clary moved fast. Faster than anyone had ever moved. At the blink of an eye she was on him. Sebastian grabbed on to her and kissed her so forcefully I would have injured Clary if she hadn't drank from the cup.

Suddenly there was a flash of light. And an arrow flew right to Sebastian. Clary grabbed it in midair and glared at Alec who had just portaled here. Her mom was there looking horrified and Simon who was glaring at Sebastian.

The rest of the shadow hunters, some werewolves, and Magnus had attacked from behind. Then Simon came running holding a sword Clary had never seen before, but somehow knew the name. It was called Glorious .

"Goddammit! Why are they here?" Clary growled frustrated and maliciously.

"Relax love," said Sebastian lightly, "We'll just leave."

Then Sebastian drove his sword into the ground and the earth trembled. A huge crater sprouted and Sebastian headed towards it. As soon as the crater appeared Jace had turned back to his normal self.

Then Sebastian turned to him and said smugly, "I have no more use for you."

Jace ran to attack him, but as soon as Clary and Sebastian jumped into it, it vanished. Jace screamed frustrated, and went to join his friends in the battle.


	3. Is Magnus Gonna Be Alright?

After the fight Jace was in Idris being questioned. Everyone was swarming around him talking so he could barely understand anything anyone was saying. He thought of Clary and how she had run off with Sebastian. Then Jace got angry, so angry he wanted to break something, but he heard a voice behind him. It was Alec. He was slightly relieved to see him, but still worried about Clary.

"Don't worry, we'll find Clary and find a way to cure her of the demon blood." Reassured Alec.

"Yeah, but we can't track Sebastian and when we find him we are probably gonna have to fight Clary, and I'm not sure I could do that."

"Then we won't fight her. We'll attack from behind and just capture her."

"She'll notice. I trained her for a year, not to mention she has extra angel blood and demon blood now to make her a better shadowhunter. After I left to give the speech for Sebastian I started bleeding on my shoulder, so before they left Clary and Sebastian had a fight. But I don't know what about. I just can't calm down."

"Stop worrying dammit! She'll be fine we all know Clary is a fighter she'll do just fine on her own. Her true self is probably trying to fight its way out right now as we speak. But you know she could actually love Sebastian and hate you for trying to get her back," Alec said sarcastically.

"You know you're a great parabatai, you can be so reassuring," Jace added ironically.

Just then Isabelle ran up to them with tears in her eyes.

"Alec I'm so sorry there was nothing I could do, but I couldn't keep it a secret from you anymore like I was told to."

"What happened Isabelle?" Alec replied concerned and worried.

"It's Magnus he was injured in the battle and he won't wake up he is losing to much blood."

Alec sprinted to the infirmary pushing everything out of his way. He ran to Magnus' side. Magnus looked so pale. Alec grabbed his hand and started to cry. Tears rushing down his cheeks. He sobbed for what seemed like hours to him, but the tears never stopped. Magnus' hand was cold and Alec felt like it was his entire fault. He was to busy with Sebastian and Jace to protect his boyfriend. He wept all over again just as the tears started to slow. Then he felt a small movement in his hand.

"Geez Alec, your gonna break my hand if you squeeze so hard," Magnus said so quietly only Alec could hear.

Alec gave his boyfriend a hug and a kiss on the cheek. He was so relieved Magnus was going to live. He loved his boyfriend and was never going to be prepared for losing him.

"Wait, how are you still alive? You were so pale and cold," Alec demanded.

"Well that's a nice greeting to give your boyfriend when you find out he isn't gonna die," Magnus replied sarcastically, then softly added, "Alec when your around you give me strength remember on Valentine's boat? You lent me the strength to start healing myself, so thank you."

"I love you Magnus."

"And I love you more Alec."


	4. The Throne Room

Soon Clary and Sebastian appeared in a throne room of a castle in a demon realm. It was beautiful. Covered in lavish rugs and tapestries. Colors everywhere, blending gorgeously. Then she saw it. An amazing pastel painting of her and Sebastian kissing. The exact scene that happened a few hours ago. And of course there were two thrones next to each other, both in rich purple and indigo velvet.

"Well I didn't know you were so good at decorating," Clary joked.

Sebastian laughed and replied, "Here follow me I'm gonna show you our room."

Clary followed Sebastian through a path of winding tunnels and hallways until Sebastian stopped. He turned and like a gentleman held the door for her as she walked in.

The room was gorgeous. Velvet couches, silk sheets on a huge bed, a ceiling mirror (she was excited about that), and beautiful art hanging on the walls. Clary jumped on the bed.

"I could get used to this," Clary said.

She pulled Sebastian towards her for a kiss. Pulling to hard -not used to her strength—and they landed on the bed Sebastian on top of Clary. This time when they kissed it was more intense. His body directly on her and he fit perfectly against her. Oh did she want him. Clary wanted Sebastian so bad. A few seconds later Sebastian's shirt had come off and Clary shirt was starting to come off. Soon they were lying together kissing, Clary wearing only a bra and underwear and Sebastian only wearing underwear.

Then she realized she wasn't even tired. She had been fighting and awake for two days straight, but wasn't even tired. Clary realized it must be an effect from Lilith's blood. Clary wouldn't ever be able to sleep again. Soon she realized how much of her humanity she had lost.

"Are you ok?" Asked Sebastian interrupting her thoughts.

"Yeah just realizing how much stuff has happened so recently."

Clary didn't care that she had lost most of her humanity, most of humanity was weakness, and now she was strong. Not to mention she had what she most desired in the world Sebastian and her second wish was about to come true. Soon they would rid the world of Nephilim. Still she felt certain emptiness as though she was missing something or someone that she just couldn't recall. But she dismissed this thought immediately.


	5. The Endarkened

When Clary got up a few hours later she went to the throne room. Of course Sebastian was already there. He was playing with the up while he waited for her.

"Well it took you long enough to get ready," said Sebastian playfully.

"So when are we leaving? I want to know, so stop keeping it a secret."

"Don't worry were leaving in about five minutes. Soon we'll have a complete army of endarkened on our side and nobody will be able to stop us."

Clary smiled her grin filled with anger and hate for the clave. She would do whatever Sebastian wanted whenever he wanted it, so Clary decided not to push on the fact she wanted to leave sooner.

A few minutes later a portal opened. Clary and Sebastian jumped through in their red gear, and soon hundreds of people were in front of them. Clary felt the satisfaction of being worshipped by the mere humans in front of her. Sebastian gave a speech and soon everyone was in line to drink from the cup. Person after person. Then there was one shadowhunter left. As soon as the last person was ready to drink Clary saw a bright light, a portal.

It was the Clave. Clary was furious, a low inhuman growl was coming from deep in her throat. The thing that infuriated her most was Jace, standing there in the front looking at her with sorrow. Clary screamed in frustration, a vile scream, as she charged forward with the endarkened following from being. They must have used some of my things in New York to track us, Clary thought. Tracking wouldn't work in the demon realm, but once she stepped one foot on the earth they could locate her.

It was a blood bath. The endarkened defeated the shadowhunters with only a little difficultly, but more just came portaling here. Soon it was Clary against Jace. Jace was just as beautiful as Clary remembered, but Clary no longer felt love in her heart for him. That would make this fight simple. Jace to in love to hurt her, but she didn't care if she hurt him.

Clary had already killed over twenty shadowhunters. She had more angel blood and demon blood. Clary was the strongest endarkened of all, maybe even stronger than Sebastian.

Clary's sword hit against Jace's creating a ray of sparks. Clary grinned deviously and Jace looked shaken by that dreadful face Clary had made.

"Please come back to me," Jace pleaded.

"Why would I come back to a lowly shadowhunter like you, if you want you can become an endarkened, but I will always be stronger than you," Clary said maliciously.

As soon as Clary finished talking, she realized her mistake. The Clave had put something in the air to make people pass out and only the Nephilim had the cure. She became dizzy and the last thing she saw before she past out was Jace's worried face looking down at her.


	6. The Angel Boy

Clary woke up on a hard cement floor, surrounded by three cement walls and one wall with adamas bars. Then she heard voices.

"Why aren't her runes vanishing? The other endarkened runes vanished when they drank from the cup, they can't bear the runes of heaven, but why can she?"

"Don't you remember? She was born with extra angel blood because Valentine fed it to her mother when she was pregnant. I guess she still has that rune power as well, but she also has more speed and strength than anyone else, not to mention that now she is wicked. That girl is probably the strongest person alive."

"Then shouldn't we just kill while she is sleeping?"

"No, the clave could have use for her, she might be able to return to her normal self and still keep her new found strength and speed because of the angel blood. And didn't you hear? That Jace guy will only help if she is kept alive and he is probably the best strategist and fighter we have."

"Oh, so shouldn't we maybe injure her so she can't escape when she wakes up?"

"Dumbass, we already tried that she is indestructible. When we tried to injure her leg with our strongest sword we have the tip broke off. The only thing that might be able to injure her is that sword the daylighter had."

"Dude I think I heard a noise. Do you think she is awake?"

"I don't know lets tell the Clave."

Clary was so furious that she accidentally let a small growl escape her throat. Then she heard footsteps. The person that stood in front of her cell was Jace.

"Did the Clave send you angel boy?" Clary said her voice filled with venom.

Jace winced and replied, "Yeah. But I also wanted to see you."

Clary reached for a throwing knife but her weapons belt was missing. Of course she thought, can't have a murderer with weapons.

"Well now that you've seen me are happy with what you see?"

"No. Clary please come back to me I love and I don't want to see you this way," Jace pleaded.

Clary heart shuddered, then she replied, "Maybe I don't want to come back to you maybe I just want to be with Sebastian."

"Clary don't you see? You want him, but you don't love him. Demons don't love they want. Don't give into Lilith's blood Clary. Your stronger than that."

"Jace," she replied with love, and then she caught herself and snarled.

"You see Clary you still have the real you inside. Please let her out."

She clawed at the bars slightly denting them, but not breaking them.

Then she whispered, "But I don't remember how to love."

Jace grabbed her hand, "Clary I love you and I will always love you. The Clave has allowed me to go inside the cell with you as long as I don't bring any weapons or steles, so I'm coming inside."

The Clave created a portal and Jace jumped through, a few seconds later he was standing next to Clary. He hugged her and Clary stiffened. Jace hugged her harder.

"Please come back to me. I miss you so much."


	7. The Demon Boy

**Sorry it has taken me so long to post. Lately I've been busy with school started and stuff but I hope you enjoy!**

Sebastian screamed with furry. Clary was taken away from him. His Clary, not Jace's. He was frantic and fuming, he wanted her back. Sebastian prepared his army for an attack. The Endarkened equipped with swords, daggers and demonic runes because the could not wear runes of the angel. They were going to raid Idris. Sebastian snickered, he would kill Jace that night whatever chance he got.

He was sitting in the throne room staring at the portrait of him and Clary kissing. He felt lonely there without her. Suddenly an Endarkened burst into the room.

"Sir, all the shadowhunters fled to Idris and are preparing for war. That is twice as many people than we have. Are you sure we can win this?"

"Yes," replied Sebastian sternly, "Of course we are going to win. We have the speed of werewolves, and the strength of vampires. If you do not stop doubting yourself I will take away your power and leave you to die."

"Yes sir."

Sebastian knew that there was no way to change an Endarkened back, but it was till a good way to threaten them. As Sebastian glanced back at the portrait he snarled. He would get Clary back no matter what.


End file.
